A Collection of Librarians

There are collective nouns for groups of animals--a sleuth of bears, a mischief of mice, a pounce of cats, a crash of rhinoceri, a shiver of sharks, a tower of giraffes but I think the birds have the best ones-- a charm of hummingbirds, a piteousness of doves, a murmuration of starlings, a murder of crows, a parliament of owls, and an exaltation of larks.

But what's the collective noun for a group of librarians? This was discussed on 50 books recently and then on Librarian Avengers .

My favorites were a hush, a stack, a collection, a catalog, an index, and a Dewey.